Lewis gordon paul



UNITED STATES PATENT OFFICE.

LEIVIS GORDON PAUIJ, OF IIUDDERSFIELD, ENGLAND.

PROCESS OF MAKING NITRITES.

SPECIFICATION forming part of Letters Patent No. 572,819, dated December8, 1896.

Application filed July 24, 1896. Serial No. 600,336. (No specimens.)

To all whom it may concern.-

Be it known that I, LEWIS GORDON PAUL, a subject of the Queen of GreatBritain, residing at Huddersfield, in the county of York, England, haveinvented certain new and useful Improvements in the Manufacture of Nitrite of Soda and Potash; and I do hereby declare the following to be afull, clear, and exact description of the invention, such as will enableothers skilled in the art to which it appertains to make and use thesame.

This invention relates to the manufacture of nitrites of soda and potashfrom the nitrates of the same by the use of. sulfur and caustic soda orpotash.

The method of carrying this invention into efiect is by heating thenitrates with the caustic alkali and adding sulfur gradually to themelted mass.

As an example of the production of nitrite of soda from nitrate of soda,I melt fifty kilos of commercial sodium nitrate in a cast-iron pan withabout twelve kilos of solid caustic soda, (containing seventy per cent.Na O.) I then add very gradually three and one-half kilos of sulfur andstir vigorously all the time. The temperature is kept at sucha degreethat the sulfur does not deflagrate when added to the melt. As soon asthe sulfur has been introduced I add another twelve kilos of cansticsoda, and then add three and one-half kilos more of sulfur under thesame conditions as before. The sulfur dissolves quickly and the nitratebecomes reduced to nitrite. When all the sulfur has been added, I raisethe tem- I am aware that sulfids have been suggested for thetransformation of nitrates into nitrites, and that they will transform acertain proportion, but I have not been able to transform a beneficialquantity by their use, and I do not claim the making of nitrite fromnitrate by the use of such sulfids when separately prepared andafterward used for the reduction of nitrate to nitrite.

Having thus described my invention, I claim as new and desire to secureby Letters Patent- The herein-described process for the pro-' duction ofan alkaline nitrite, which consists in melting an alkaline nitratetogether with the caustic compound of the same alkali, and adding sulfurto the melt, substantially as specified.

In testimony whereof I have affixed my signature in presence of twowitnesses.

LEWIS GORDON PAUL.

Witnesses:

CHAS. MILLS, THOMAS H. BARRON.

